intro and conventional bridgework Flashcards
What are the reasons for treating tooth loss?
Aesthetics
Function
Speech
Maintenance of dental health - adjacent teeth can tilt or overlap
What is a bridge?
A prosthesis which replaces a missing tooth or teeth and is attached to one or more natural teeth or implants
What is the difference between adhesive bridges and conventional bridges?
Adhesive bridges have palatal wings
Conventional bridges are held on by crowns
Name 4 general indications for bridgework
Any from:
- function and stability
- appearance
- speech
- psychological reasons
- systemic disease
- cooperative patient with good oral hygiene
Name 4 local indications for bridgework
Big teeth
Heavily restored teeth
Favourable abutment angles
Favourable occlusion
Name 4 general contra indications for bridgework
Any from:
- uncooperative patient
- MH contraindications eg - metal allergy
- poor oral hygiene
- high caries rate
- periodontal disease
- large pulps - in young patients
Name 4 local contraindications for bridgework
Any from:
- high possibility of tooth loss in future
- poor prognosis of abutment
- length of span too great
- ridge form and tissue loss - replicating gingiva is difficult
- tilted and rotated teeth
- endodontic disease
- periodontal disease
What is an abutment?
A tooth which serves as an attachment for a bridge
What is a pontic?
An artificial tooth which is suspended from the abutment tooth
What is a retainer in bridgework?
The extra-coronal or intra-coronal restorations that are connected to the pontic and cemented to the prepared abutment teeth
What are connectors in bridgework?
Component which connects the pontic to the retainer
What is the edentulous span?
The space between natural teeth that is to be filled by a bridge or partial denture
What is a saddle?
The area of the edentulous ridge over which the pontic will lie
What is a pier?
An abutment tooth which stands between and is supporting two pontics, each pontic being attached to a further abutment tooth
Describe a unit in bridgework?
Either a retainer or a pontic eg - a bridge with two retainers and one pontic = 3 unit bridge
Describe the different types of conventional bridges
Fixed-fixed - retainers at either side
Fixed cantilever - retainer only at one side
Fixed movable - fixed connector distally and movable connector mesially
Name 3 uncommon bridge designs
Fixed-movable bridge
Hybrid bridge
Spring cantilever bridge
Name 3 advantages of conventional fixed-fixed bridges
Robust
Maximum strength and retention
Abutment teeth can be splinted together in perio cases
Can be used in longer spaces
Lab construction is straightforward
Name 3 disadvantages of conventional fixed-fixed bridges
Prep difficult (parallel tooth preps needed)
Prep must be minimally tapered
Common path of insertion for abutments is difficult
Removal of tooth tissue causes danger to pulp
Describe the ideal taper in a conventional fixed-fixed bridge and the disadvantage of overtaper
Aim for 5-7º
Can go as far as 10º
If overtaper, crown can slide off in multiple directions
Describe a fixed movable bridge
Bridge in 2 parts - crown, pontic and dovetail, then separate crown with slot for dovetail. Uses two paths of insertion
Name 3 advantages of a conventional fixed-moveable bridge
Any from:
- prep doesn’t require a common path of insertion
- each prep is designed to be retentive independent of others
- conservative of tooth tissue
- allows minor tooth movement
- may be cemented in two parts
Name 3 disadvantages of fixed-moveable bridges
- length of span limited
- lab construction complicated
- difficulty in cleaning beneath moveable joint
- can’t construct provisional
- need patient with good oral hygiene
Name 3 advantages of conventional cantilevered bridges
Conservative design
Lab construction straightforward
No need to ensure multiple tooth preps are parallel
Name 3 disadvantages of conventional cantilever bridges
Short span only
Rigid to avoid distortion so prone to fracture
Mesial cantilever preferred as abutment teeth more posterior are likely to occlude first
Describe a hybrid bridge
Rarely see these
One retainer is conventional prep, the other retainer is minimal prep
Metal wing likely to debone, not noticeable which leads to leakage
Describe a spring cantilever bridge
Rarely see these
One pontic attached to the end of a metal arm that runs across the palate to a riding connector on the palatal side of a retainer
Name 2 advantages of a conventional spring cantilever bridge
Any from:
- useful if spacing present between upper incisors
- do not need to restore adjacent teeth
- useful if posterior already has a large direct/indirect restoration
Name 2 disadvantages of conventional spring cantilever bridges
Any from:
- can only be used to replace upper incisors
- difficult to clean beneath palatal connector
- may irritate the palatal mucosa
- difficult to control movement of pontic due to springiness of metal arm and displacement of palatal soft tissues
What makes a good abutment tooth for a bridge?
- Must be able to withstand the forces previously directed to the missing teeth
- Supporting tissues should be healthy and free of inflammation
- Crown to root ratio optimally 2:3, minimally 1:1
